Are you trying to figure out if its possible that a previous owner disabled the PS, or if you can disable it since its not working? You can buy serpentine belts of nearly any length, so it may be possible to bypass it...but then the steering would be unmanageably heavy. I think it's unlikely anyone did that. PS pumps aren't too expensive, or it may even be a clog in it or something. I'd just get it fixed before driving the car again. Your steering rack may also be the culprit...seals can fail with time causing PS fluid blow-by and reducing pressure, but even the worst steering rack should generate some hydraulic assistance. Usually only a PS pump failure can cause complete loss of power steering. Have you tried changing your PS fluid?
No 7th gen celica came without PS, at least in North America for sure, and probably in all national/regional specs. The alt would be rack and pinion, but that isn't really used anymore on modern production cars and senseless for Toyota to think of implementing.
2000 GTS 6-speed. Performance Mods: Apexi Power FC, BC Racing DR coilovers, Injen CAI, Catback exhaust, EBC 'USR' rotors, Carbotech XP8 pads, Stoptech brake/clutch lines, Castrol SRF brake fluid, Exedy stage 2 clutch, Mishimoto radiator, Moroso oil pan, 11# flywheel, Braille 11.5# car battery, Energy urethane suspension/motor bushings, BFGoodrich G-force tires.